Vent plug for permanent molds



W. S. ANDERSON VENT PLUG FOR PERMANENT MOLDS Filed March 9, 1925 Wa/fer 5. fifiaerson. INVENTOR.

A TTORNE Y.

Iii W Patented a... 40, 1927.

' UNITED STATES wanna a. memoir, on

PATENT OFFICE.

VENT PLUG FOB PEBIANENT HOLDS.

Application manna a, 1925. Serial in. 13,994.

The object of this invention is to provide improved venting means for metal molds. One of the most serious difliculties experienced when casting iron in 'metalmolds is I that air is trapped, causing imperfections in the castings. If holes are drilled sufliciently large notto clog with dirt and dust, iron flows in and seals them.

Figure 1 shows a mold in elevation. Figure 2 shows across sectional elevation on the plane 22 of a pair of molds. Figure 3 shows a cross sectional elevation on the plane 33 of Figure 2.

In the figures, A is the s rue. B is the gate leading to the mold G. is a lug. E is, a boss provided for said plug. e Tpiug D is provided with three flats F F F. ese flats are arranged to provide gaps preferably .008" to .010" in width (not over .015"). G and H are the mold castings themselves in p which the'mold cavities O C are rovided. The sprue A, gate B, and mold cavity C are surrounded by ahead J which provides the matching surface between the two halves G H of the mold, as shown in the Phillips Patent #1099997.

Ogemfima-The two halves G H of the mol having been brou ht together so that the matching surface J I are in contact with I each other, the iron is poured in through the rue holes A, gate B, into the mold cavity As the mold cavity C fills up with molten metal the displaced air rises and escapes through the three flats F F F arrarged on the circumference of the plug D. y this means a ood sound casting is produced free from sur ace and other imperfections due to trapped air. The ventsl F FF are of such a size that the iron cannot follow the air through it If holes having the same dimensions as the flats F F F are drilled into the casting they easily clog up with dirt and dust, and moreover holes assmall as this are expensive to drill because oft-he tool breakage.

These molds are intended to be coated with athin refractory coating and a superimposed coating of lampblack, as set forth in the Meloche Patents #1453593 and #1492694.

Iron is poured in the mold when the mold is at a relatively high temperature above 600 F.

For the sake of clearness the ejection de- A vices used in conjunction with these molds have been omitted. What I claim is 1. In a metal mold having a cavity therein, a vent plug adapted to close said cavity and gzovided with a flat surface, an air passage tween the wall of said cavity and said plug opposite said flat surface not over .015".

2. In a metal mold, a'vent plug provided with a depression on the surface of the plug through which air may escape but iron cannot flow.

3. In a metal mold having a cavity therein, a cylindrical lug adapted to close said cavity, a relative y wide gap between the plug and the wall of said cavity of such a width that moltenmetal cannot flow therethroufilh but through whichair can esca e.

4. a metal mold having a cavit therein, a vent plug adapted to close sai cavity, an opening between said plu and said cavity havin a maximum opemng-of .015" in width, and openin being located in that portion of the mo (1 in which air would otherwise collect.

In testimon whereof I aflix my signature.

VALTER S. ANDERSON. 

